PEUCEDANUM, UMBELLIFER&. 253 
high with a short subterranean stem from a deep-seated fusiform root: 
leaves bipinnate, the ultimate divisions short and linear-oblong; umbel 
unequally 1-5-rayed, with inyolucels of more or less united, often toothed 
bractlets: fruit sessile or nearly so, ovate rough puberulent, 3 lines long, 
with narrow wings, oil-tubes obscure, seed face plane. Simcoe Mountains, 
Washingten. 
P. Cous Watson 1. c. xxi, 453. Glabrous or slightly puberulent, with 
roughish scapes 2-6 inches high from a nearly globose tuber 6-12 lines in 
diameter: leaves pinnate: leaflets 3-7 parted or cleft or even entire; ulti- 
mate divisions linear-oblong: umbel unequally 3-10-rayed, with involu- 
cels of short oblong-ovate scarious-margined bractlets, rays from nearly 
wanting to 2 inches long; pedicels short: fruit oblong, more or less puber- 
ulent, 2-4 lines long, 1-2 lines broad, with wings about half as broad as 
the body, and prominent dorsal and intermediate ribs; oil-tubes large, 
filling the intervals: 4-6 on the commissure: seed-face plane with central 
longitudinal ridge. On high gravelly ridges, John Day Valley, Oregon. 
. P. ambiguum Nutt. T. & G. FI. i, 626. From low acaulescent to a 
foot high and caulescent; glabrous: root tuberous, usually moniliform: pet- 
ioles much dilated at base: leaves 1-2-pinnate with more or less elongated 
linear leaflets, the upper often more dissecte *: umbel unequally 8-18-rayed 
with mostly no involucels: rays 1-4 inches long; pedicels 2-3 lines long: 
fruit narrowly winged: oil-tubes 20n the commissure. Oregon to Brit. 
Columbia, Idaho and Montana. 
Var. leptocarpum C. & R, Rey. Umb. 59, Fruit sessile or nearly so 
. RiAbing a close somewhat diyaricate cluster: rays few and very unequal. 
regon. 
P. cireumdatum Watson l. c. xxii, 478. Stem solitary from a deep- 
seated constricted tuber, glabrous or puberulent a foot or less high: leaves 
ternate-quinate. the ultimate divisions linear 1-4 lines long: umbel un- 
equally 6-12-rayed, with involucels of conspicuous broadly oblanceolate 
bractlets becoming scarious; rays 4-34 inches long; pedicels very short: 
fruit oblong elliptical, glabrous, 3-4 lines long 114 lines broad, with nar- 
row wings and very prominent dorsal and intermediate ribs: oil-tubes 4 
on the commissure: seed-face concave with a prominent central ridge. 
Oregon and Washington to Dakota. 
§ II. Stout, glabrous only in P. Grayi, from large roots: leaves 
mostly large and very finely dissected, the ultimate segments filiform 
6r narrowly linear: fruit wings more than half as broad as the body: o1l- 
tubes 1-3 in the interyals, (solitary in P. Grayiand P. macrocarpum). 
* Flowers yellow: fruit glabrous: short caulescent. 
P. Grayi C.&R. Bot Gaz. xiii, 209. P. millefolium Watson. Gla- 
brous, peduncles 2-20 inches long numerous from a thick perennial root: 
leaves ternate-pinnately decompound, the ultimate segments linear, 
elongated or short cuspidate, very numerous: umbel rather equally 6-16- 
rayed, with involucels of distinet linear-subulate bractlets; rays 1-3 inches 
long; pedicels 5-8 lines long: fruit oblong 4-8 lines long, 2-5 lines broad, 
with filiform dorsal and intermediate ribs: oil-tubes usually solitary in 
the intervals, 2-4 on the commissure. Common on dry rocky banks Ore- 
gon and Washington to Utah. 
bari” Flowers white. 
P. euryearpum C. & R. Rev. Umb. 61. Somewhat caulescent 6-12 
inches high more or less pubescent from a long biennial caudex terminat- 
ing below in a fusiform tuber: leaves bipinnate, segments pinnately in- 
scised, ultimate divisions ovate or shortly linear: umbel somewhat 
